I just finished assembling and upgrading a Xeon 3GHz quad core (equivalent of i7-920) which handles 8 threads. I'm pleased with the result which so far has cost slightly more than $110 USD. Much faster than my old Athlon X2. I'm still using a GTS 250 and I need much more GPU to balance the system. One thought is a new GTX 950 when coupons at NewEgg bring it below $100 (total max, or the spouse stops cooking dinner). Another is to haunt eBay like I did for the system, but I am a bit concerned that the real condition of a used card is unknown. It was 'ok' for the system, since nobody ever bought a new Dell Precision T3500 to overclock it. It lived under a desk for 4 years and then was outplaced in a gentle manner. So what is your experience? Is a used video card a feasible purchase or not?